Cannot connect to TrueNas by servername only IP

I have a strange issue where I cannot connect to SMB shares via the servername of my TrueNas server. It shows up on my windows clients just like my other servers, but if I double click to connect it throws a windows networking error saying “Windows cannot access \MyTrueNasServer” error code 0x80070035. So the TrueNas servername is visible in the windows network, however it is not accessible.

Further investigation - using cmd and ping - Ping request cannot find host MyTrueNasServer

I can connect - by using the \{server ip addr}. I have full SMB functionality from there.

I do have other NAS servers on the network which resolve fine via the SERVER_NAME and SMB works fine.

Note: I have a test laptop that produced the same symptoms until as part of my Univention server testing I changed it’s DNS server to the Univention server instead of my pfSense gateway/router. I don’t know how that changed anything since the Univention server does not as yet maintain any information about my TrueNas and neither Truenas or Univention are configured to recognize each other on the network or rely on services from the other.

Any ideas on how to troubleshoot this?

TIA

You need to have a proper DNS entry for the TrueNAS in whatever is handling DNS. A way to get around the DNS issue is to go to each device and add a host entry.

Yes - this would solve the issue, however, somehow the other devices on the network are working without DNS entries, perhaps they are using Bonjour or Netbios somehow. I would love to be able to determine how clients are actually resolving the name. Oddly when I ping the ‘net bios’ name for my Truenas from a Windows 10 computer that is part of the active directory that I am testing, it resolves to TrueNas.local and I get ping replies… there is not record on the DNS server that maps to TrueNas.local, so somehow that name is broadcasted or queried from the TrueNas itself since the DNS name is TrueNas.MyLocalDomain.local not TrueNas.local (which is set on my TrueNas).

Do you know of a tool or method to determine where and by what mechanism client computers are deriving their mappings? (I suspect that several different name resolutions are at work, DNS is actually easy to ‘Dig’ but the other mechanisms I am not sure of).

If you are using pfsense you can register DHCP leases in DNS forwarder, except that it registers the DHCP static mapping addresses instead.
https://docs.netgate.com/pfsense/en/latest/services/dns/resolver.html

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That’s interesting, so the idea would be to point it at my internal DNS server (which would in turn forward queries to the internet for non local resolution)?

Do you happen to know if pfSense supports being a slave DNS? It would be ideal if the pfSense could still be the DNS server for both the internal and external network, and cache or slave records from the internal DNS for the AD.

I don’t think it can do that, but the DNS name registration should work for using DNS in AD as well with Windows being the DNS server.

If using Active Directory, did you add the NAS server name there? If all pcs point at AD then adding the DNS name there will resolve for all.